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isbndb.com - free books & ISBN database
ISBNdb.com project is a database of books providing on-line and remote research tools for individuals, book stores, librarians, scientists, etc. Taking data from hundreds of libraries across the world ISBNdb is a unique tool you won't find anywhere else.
The Internet Archive, a 501(c)(3) non-profit, is building a digital library of Internet sites and other cultural artifacts in digital form.
Internet Archive: Digital Library of Free Books, Movies, Music & Wayback Machine
is the most comprehensive scientific research tool on the web. With over 440 million scientific items indexed at last count, it allows researchers to search for not only journal content but also scientists' homepages, courseware, pre-print server material, patents and institutional repository and website information.
Scirus - for scientific information